Matt16

My back window was slow going up and so I called Toyota. They wanted something close to $1000 to fix the rear window JUST FOR PARTS. This is how you can fix it properly for about $15 in about an hour.

Parts and Tools

• SANYOU SRD-S-112D*
• rosin core solder
• utility knife
• soldering iron
• solder sucker
• white lithium grease
• Philips screw driver
• 12V power source to test you motor window
• some wire to jump the window motor

*Relay used:
I called up a local electronics parts store and described the relay. Here's the description of the relays used:

12-volt miniature automotive
PCB relay with 5 pins
320 ohm coil
approximate OEM dimensions: 22mm long X 16mm wide X 15.5mm high

They then gave me the Sanyou relay shown.

From this site: http://www.geocities.com/dkwalker/te..._relay_fix.pdf

Symptoms
Back window was slow to go up but went down fast enough. It would close have way at a reasonable speed them slow to a crawl as if the motor was really straining. When the engine was on, the window would usually make it to the top, but not always. When the engine was shut off, I had to help the window up to the top with my hand.


Diagnosis
I removed the carpeted panel on the tailgate and removed the six screws holding the black metal panel underneath. This is all very self evident when you start taking it apart.

This is was you will see when the panels are removed.


I then unplugged the motor from its blue connector. The rear window goes up and down by switching the + and - terminals via a relay which will be discussed later.

I jumped the motor by taking spare 12V battery and touching it to the wires in the plug (see below). The motor worked perfectly in both the up and the down directions. I thus determined it was not the motors that were to blame for the slow back window.


The Problem
First off, some background info. The rear window motor circuit is energized via a relay. A relay is a simple electrical switch that when a first circuit is energized, it completes a second circuit.

In this application, Toyota used a 6A relay when it seems they should have used a heavier duty relay of 10A or so. After time, the contacts where the second circuit is completed wear out and no longer conduct electricity as well. Thus, the motor does not receive enough power to raise the window.

The Fix
I tried cutting the tops of the relays off and cleaning the contacts, but this did not work at all. I wouldn't bother. Some people have simply swapped the wiper motor relay with the window motor relay. The wiper relay is in better condition usually because it is not used as heavily. It would probably work, but your wiper would be compromised.


I decided to replace the relays as they were cheap and as it turns out, easy to find.

I called around to see if I could find replacement repairs from the OEM (Omron). However, I was told that these Omron relays were specially built for Toyota and you cannot buy them. The electronics part store (Main Electronics in Vancouver, BC) were very helpful and found a 5 pin relay that is smaller and would fit. It also has a higher amperage rating of 10A which should it should last the life of the truck.

The control module is located by the tailgate on the driver’s side. It is just back from the storage compartment. Pull back the panel and you will see two bolts connecting the module to the body. Unbolt, unplug and remove the black box.



Here’s a pic of the location with the module removed, and the connector showing (centre).


Open it up and you will see the relays and assorted circuitry. Going from left to right the functions of relays are
1. WINDOW UP 2. WINDOW DOWN 3?4? (Please tell me if you know which is which)



Basically, you have to remove the two relays (black boxes) closest to the black cylindrical bit on the left side of the photo below. I used a spring loaded solder sucker. I then soldered on the new relays, which are smaller, but heavier duty. The black cover over the two other relays is electrical tape, as I had tried to clean the contacts to no avail. The relays will work with the tops off and tape covering them.



Here are the new relays, they're made by SANYOU. The part number appears to be SRD-S-112D. They are smaller than the OEM relays and fit just fine. The pins are in the same positions and its simply a matter of removing the old and soldering in the new relays.


Reassemble and now you should have a working rear motor. My window goes up in about 5 seconds now. Anyways, it works a lot better and didn’t cost much.


Supplementary repairs

Grease the runners where the motor contacts the window with lithium grease. This also helps protect against rust, though it’s probably rusty already.



While you're at it, I'd replace the other two relays as well on the board as well. One controls the rear wiper motor and the other I think controls the rear defroster although it could control the function that lifts the wiper off the glass...not sure. Might as well replace them while you're at it though.

__________________
1990 Toyota 4Runner 22RE 5spd
Rear Aussie Locker [click here for the review] *Nokian Vativa A/T tires* OME suspension* York OBA* pretty much stock.


Toyota FAQ link
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